Elevated intraocular pressure is the main cause of a condition called glaucoma, which gradually damages the optic nerve, resulting in permanent blindness if left untreated. Recently, some researchers have published study results suggesting that scleral contact lens wear could increase intraocular pressure in healthy individuals.
As Dr Patrick J. Caroline and Dr Mark P. Andre write in the latest issue of Contact Lens Spectrum, there are several theories explaining the potential impact of scleral contact lenses on intraocular pressure (e.g. suction forces under the scleral lens or disruption to angle and trabecular meshwork anatomy), but none of them is confirmed by evidence.
What is more, the measurement of intraocular pressure during contact lens wear is challenging, the experts point out. There are only a few techniques available, sometimes providing inconsistent results. A case series carried out recently, Dr Caroline and Dr Andre stress, shows the problem very well. During the study, its authors encountered variable results and could not use the recommended technique in some subjects due to their ocular anatomy.
The problem needs to be investigated, the experts conclude, but reliable methods of measurement have to be developed first.